Stepwise displacement of catalytically active gold nanoparticles on cerium oxide.

Kuwauchi, Yasufumi; Takeda, Seiji; Yoshida, Hideto; Sun, Keju; Haruta, Masatake; Kohno, Hideo · Nano Lett · 2013

basic_science · Level V

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Abstract

Aberration-corrected environmental transmission electron microscopy (ETEM) proved that catalytically active gold nanoparticles (AuNPs) move reversibly and stepwise by approximately 0.09 nm on a cerium oxide (CeO2) support surface at room temperature and in a reaction environment. The lateral displacements and rotations occur back and forth between equivalent sites, indicating that AuNPs are loosely bound to oxygen-terminated CeO2 and may migrate on the surface with low activation energy. The AuNPs are likely anchored to oxygen-deficient sites. Observations indicate that the most probable activation sites in gold nanoparticulate catalysts, which are the perimeter interfaces between an AuNP and a support, are not structurally rigid.